G20 — Parkinson's disease
Is G20 billable?
No — G20 is a non-billable header code. G20 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 5 billable codes beneath G20.
Billable codes under this header
- G20.CParkinsonism, unspecified
- G20.A1Parkinson's disease without dyskinesia, without mention of fluctuations
- G20.A2Parkinson's disease without dyskinesia, with fluctuations
- G20.B1Parkinson's disease with dyskinesia, without mention of fluctuations
- G20.B2Parkinson's disease with dyskinesia, with fluctuations
G20 at a glance
| Code | G20 |
|---|---|
| Description | Parkinson's disease |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Use additional code
Report an additional code alongside G20 to fully describe the condition. G20 is sequenced first.
- code, if applicable, to identify:
- dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
- dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
- dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
- dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
- dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
- mild neurocognitive disorder due to known physiological condition (F06.7-)
Inclusion terms
Alternative wording in documentation that is classified to G20.
- Hemiparkinsonism
- Idiopathic Parkinsonism or Parkinson's disease
- Paralysis agitans
- Primary Parkinsonism or Parkinson's disease
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G20, but a patient may have both at the same time. When documentation supports it, G20 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
What codes fall under G20? (3)
How long has G20 existed?
G20 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
- FY2024: G20 stopped being billable
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with G20?
ICD-10-CM declares these codes mutually exclusive with G20 — exactly one of each pair can be correct for a given encounter.